Hi yes i remember the U/G very well
brilliant filter cheap simple and foolproof well almost
Nowadays tanks are alot better for the more modern types of filters,and easier to keep clean!
As for moving a tank,the same rules apply regardless of size or fresh,saltwater or coldwater!
Number 1 keep as much water as possible!
Keep the filters moist - this keeps the bacteria alive.
Always completely empty the tank before moving! Including gravel!
Move the fish in bags like when you buy them! Double bag'em,tape the corners and don't put too many fish in any one bag.
Don't feed on the day of moving and feed sparingly after for a few days and plenty of small water changes.
So you will need plenty of containers for the water,loads of fish bags and buckets for putting the gravel etc in. Also the golden rule is don't rush take your time and all will be well